Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The frequency intervals seen in blood flow oscillations, and their physiological origins.
| Interval | Frequency (Hz) | Physiological origin |
|---|---|---|
| I | 0.6–2.0 | Cardiac activity |
| II | 0.145–0.6 | Respiration |
| III | 0.052–0.145 | Myogenic activity |
| IV | 0.021–0.052 | Neurogenic activity |
| V | 0.0095–0.021 | Endothelial metabolic activity |
| VI | 0.005–0.0095 | Endothelial activity |
